The 1:1 addition of .alpha.,.beta.-unsaturated esters, ketones, and nitriles to activated "donor" compounds, for example, silicon- or tin-containing "donor" compounds, is well known. Such reactions may be referred to as Michael type addition reactions and are catalyzed by bases, such as a fluoride or cyanide, or by Lewis acid, such as zinc chloride, boron trifluoride, titanium tetrachloride, or hydrogen bromide.
K. Saigo et al., Chem. Letters, 2, 163 (1976) disclose that when methylvinyl ketone or cyclohexenone is employed as a Michael acceptor in the presence of O-silylated ketene acetals and titanium tetrachloride, the desired product is obtained in low yields and a polymeric by-product is produced. The polymer was not isolated or identified and means are disclosed for minimizing the by-product by modifying the titanium tetrachloride catalyst by including therewith tetraisopropyl titanate.
U.S.S.R. Pat. No. 717,057 discloses organosilicon acetals of the formula EQU RO-CH(CH.sub.3)-OSiR'.sub.3-n (OR").sub.n,
and their use as intermediates in the preparation of perfumes and in the production of polymers and flotation agents, wherein R is C.sub.3 H.sub.7, C.sub.6 H.sub.5, CH.tbd.CCH.sub.2, CH.tbd.CC(CH.sub.3).sub.2 or menthyl; R' is C.sub.1-4 alkyl or C.sub.6 H.sub.5 OCH(CH.sub.3), and n is 0 or 1.
U.S.S.R. Pat. No. 715,583 discloses trimethylsiloxyethyl esters of the formula RC(O)X-CH(CH.sub.3)-OSi(CH.sub.3).sub.3, useful as intermediates in the manufacture of medicinals, plasticizers, and polymers, and as agricultural pesticides and perfumes and in food manufacture, wherein X is oxygen or sulfur and R is lower alkyl, chloroalkyl or optionally substituted alkenyl.
Stork et al., JACS 95, 6152 (1973) disclose the use of .alpha.-silylated vinyl ketones to prevent the polymerization of simple alkyl vinyl ketones via their enolate ions during Michael addition reactions.
The use of trialkylsilyl groups as temporary protectants for hydroxyl functions, removal by subsequent hydrolysis, is well known in the art, for example, Cunico et al., J. Org. Chem. 45, 4797, (1980).